Retargeting has emerged as an effective way of advertising via the Internet. Retargeting allows an advertiser to display an ad to a consumer after the consumer has left the advertiser's website. As the consumer proceeds to other websites, advertisements may be provided to the user by the advertiser on the other websites.
To retarget potential customers, an advertiser stores information on a user's computer in the form of a cookie to indicate that the user visited a particular page. For example, if the user accesses a page relating to a particular DVD player, the advertiser's website may place a cookie corresponding to the web page on the user's computer. When the user leaves the web page, the cookie remains on the user's computer.
The advertiser purchases ad space from a publisher or an ad network. When the user accesses a web page associated with the publisher or ad network, the cookie is read from the user's computer. The publisher or ad network may then select an ad to be shown to the user according to the cookie information. Thus, the publisher or ad network may present an ad for the previously viewed DVD player, which may be clicked by the user to return to the advertiser's web page to purchase the DVD player.
While retargeting can be quite effective, its reach is limited by the popularity of the publisher and/or size of the ad network. To reach more consumers, the advertiser contracts with multiple publishers and ad networks, increasing the cost and complexity of the retargeting. Use of multiple, unrelated publishers and ad networks, however, creates additional problems, such as reduced control, overlapping reach among publishers and ad networks, and “overselling” due to a user receiving multiple ads for the same item via different publishers and ad networks.